# City Investigator

- **Event:** [Meta Global AI Developer Hackathon](https://cerebralvalley.ai/e/meta-ai-developer-hackathon)
- **When:** Oct 26, 12:00 PM – Nov 4, 9:00 PM (EST)
- **Where:** Online
- **Team:** [Yirong Ding](https://cerebralvalley.ai/u/DDDDD)
- **GitHub:** https://github.com/yirong-ding/city-investigator
- **Demo video:** https://youtu.be/scoLoaOLxHs
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/5038

A street's problems are recorded in a dozen places, and none of them are set next to what a resident actually sees. City Investigator starts from a street photo and a question, for Brooklyn Community District 6. SAM 3.1 segments the photo. Muse Spark then investigates with tools, reading 311 complaints, permits, sensor readings and the city's flood model, and asking SAM 3.1 to look at the photo again when it needs to. The result is a short answer of labeled claims, linked to a map and a timeline, and a view of the place in 3D.

Five ideas shape it:
A. Records against reality. The photo and the records are checked against each other: agree, disagree, or a gap, and every source says what it cannot see.
B. Evidence, not guesses. Muse Spark investigates with tools, and every claim must cite its evidence or a code checker drops it.
C. Grounded proposals. Next steps only through real channels, backed by how similar reports ended here, plus at most one sourced idea from elsewhere; no promises. Each comes with a draft to send, and Muse Image shows it done in the resident's own photo.
D. Needs at stake. Each finding is tagged with Jan Gehl's criteria: protection, comfort, enjoyment.
E. An honest 3D twin. The evidence placed in the city (Valdrada, an open-source 3D New York), and After shows proposals at their real scale, not a made-up prediction: three rain gardens against the modeled flood, under one percent of the water.

Under "What could be done", each proposal names a real channel: one click and Muse Spark drafts the 311 report or the letter to send, from the checked claims only; another and Muse Image redraws the resident's photo with the proposals done, marked as an AI illustration, not evidence.

Across 26 places in the district, the records and the photo disagree at 8. All 276 claims passed the checker, Muse Spark chose to ask SAM 3.1 to look again 11 times, and the explanations cost about $2.38 in model calls. Nine kinds of street problems are covered, and 126 offline tests pass without a key.

City Investigator is a research aid, not an official determination.

## More from Meta Global AI Developer Hackathon

- [Quanticomp](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/5035)
- [Snaplog](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/5036)
- [Wonderfruit](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/5037)
- [Md Fahad Mia](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/5039)
- [SaveBell](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/5040)
- [Dragology](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/5041)

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Markdown version of https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/5038. Site index for agents: https://cerebralvalley.ai/llms.txt · full text: https://cerebralvalley.ai/llms-full.txt